Adjustable temperature regulated faucet

ABSTRACT

A valve assembly for a faucet assembly includes a housing, a thermal motor and a sealing element. The housing includes a first inlet that receives water from a first source, a spout outlet in fluid connection with the first inlet, and a second inlet that receives water from a second source. The thermal motor is within the housing and imparts linear force in an axial direction. The sealing element is operably coupled to move in response to the imparted linear force, and is configured to engage a seating element to form a seal between the second inlet and the spout outlet. The seating element is disposed axially between the motor and the sealing element, and movement of the sealing element in the axial direction breaks the formed seal to allow fluid flow within the housing between the second inlet and the spout outlet.

This application is a divisional application of U.S. Ser. No.14/207,564, filed Mar. 12, 2014, which claims the benefit of U.S.Provisional Application Ser. No. 61/780,585, filed Mar. 13, 2013, whichis incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to faucets, and moreparticularly, to faucets having temperature regulation.

BACKGROUND

Temperature-regulated faucets are used, at least in some cases, toensure that the water ejected from the faucet does not have a harmfullyexcessive temperature. Various methods have been used to carry this out,including the use of thermostatic valves that force inclusion of coldwater in the ejected water if the water temperature is above athreshold.

Prior designs suffer many drawbacks, including lack of reliability, lackof easy adjustability, and manufacturing cost. For example, at leastsome building codes require the use of an ASSE 1070 mixing valve toinsure outlet temperature never exceeds 110°. Currently, faucets meetthis code by the use of an under-the-counter thermostatic mixing valve(TMV). The inherent flaw to this design is that the TMV is underconstant pressure and relies on independent spring check valves toprevent a cross connection within the plumbing system. In other words,failure or degradation of the under-the-counter mixing valve can affectthe plumbing system, as opposed to merely resulting in poor operation ofthe faucet.

Furthermore, spring check valves are easily affected by dirt and debriswithin the waterway and the thermal expansion (caused by heating thewater) creates a higher pressure on the hot water lines. This higherpressure has a tendency to creep into the cold lines and create evenlarger problems to the domestic water system.

Some alternative designs, such as that shown in U.S. Pat. No. 6,257,493address this issue by implementing a thermal motor and a cold waterbypass mixing chamber that are upstream of the on-off features. However,this design is a single handle design unsuitable for heavy dutyapplications, is not adjustable, and has high relative manufacturingcosts.

There is a need, therefore, for a temperature regulated faucet designthat addresses one of more of the above-referenced drawbacks.

SUMMARY

The objective of the inventive faucet design disclosed herein is tothermostatically control the outlet temperature of water in thecommercial faucet industry and eliminate cross connection associatedwith current designs. At least some embodiments of the present inventionmoves a TMV assembly above the on/off features of a two-handled faucet,and employs vertically separated mixing chamber and cold-water bypass,and eliminates the potential for cross connection. The TMV assembly insome embodiments is further configured to selectively seal thecold-water bypass using a seal that seals with the pressure of the coldwater in the bypass.

In any event, because the TMV is now located above the hot and coldseats of the faucet, there is no chance of pressurizing the upper faucetbody with the spout open to atmosphere. And when the hot and cold seatsare closed, no water enters the mixing well.

In one inventive feature, the placement of the mixing well above the hotand cold on/off features allows for the TMV assembly to be placed in away that it may be readily adjusted. In a preferred embodiment, theadjustment access to the TMV is located under the spout where the spoutcouples to the frame. In another feature, standard two-handle cartridgesare used for on-off of hot and cold water, while a similar or identicalcartridge casing is used for the TMV, thereby allowing for ease ofmanufacture.

A first embodiment is a faucet comprising a mixing chamber, a bypasschamber, a hot water actuator, a cold water actuator, and a valveassembly. The mixing chamber is in fluid communication with a spout. Thebypass chamber is operably coupled to a source of cold water. The coldwater actuator is operably coupled to provide, upon actuation, coldwater to the mixing chamber. The hot water actuator is operably coupledto provide, upon actuation, hot water to the mixing chamber. The valveassembly has a seal configured to move in a direction away from thespout responsive to a temperature of water in the mixing chamberexceeding a threshold, such that fluid connection is provided betweenthe bypass chamber and the mixing chamber.

In another embodiment, a valve assembly includes a housing, a thermalmotor and a sealing element. The housing includes a first inlet thatreceives water from a first source, a spout outlet in fluid connectionwith the first inlet, and a second inlet that receives water from asecond source. The thermal motor is within the housing and impartslinear force in an axial direction. The sealing element is operablycoupled to move in response to the imparted linear force, and isconfigured to engage a seating element to form a seal between the secondinlet and the spout outlet. The seating element is disposed axiallybetween the motor and the sealing element, and movement of the sealingelement in the axial direction breaks the formed seal to allow fluidflow within the housing between the second inlet and the spout outlet.

The above-described features and advantages, as well as others, willbecome more readily apparent to those of ordinary skill in the art byreference to the following detailed description and accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a faucet incorporating an embodimentof the invention;

FIG. 2 shows an exploded perspective view of the faucet of FIG. 1;

FIG. 3 shows a cutaway view of the faucet of FIG. 1;

FIG. 4a shows a plan view of a thermostatic mixing valve (TMV) assemblyaccording to at least one embodiment of the invention that may be usedin the faucet of FIG. 1;

FIG. 4b shows a cutaway view of the TMV assembly of FIG. 4a wherein theTMV assembly is in the bypass mode.

FIG. 4c shows an exploded view of the TMV assembly of FIG. 4 a;

FIG. 5 shows another cutaway view of the TMV assembly of FIG. 4a whereinthe TMV assembly is in the normal mode;

FIG. 6 shows a cutaway view of the TMV assembly of FIG. 4a wherein theTMV assembly is in the shutdown mode;

FIG. 7 shows an alternative faucet assembly in which the TMV assembly ofFIG. 4a may be employed.

DETAILED DESCRIPTION

FIGS. 1, 2 and 3 show different views of a faucet 10 that incorporatesat least one embodiment of the present invention. In the embodimentdescribed herein, the faucet 10 is a two-handle, cartridge style, castbrass design. The faucet 10 includes a faucet body 12, a hot wateractuator 14, a cold water actuator 16, a thermostatic mixing valve (TMV)assembly 18, retaining nuts 20, handles 22 a and 22 b, an O-ring 24,retainer members 26, a bushing holder 28 and a spout 30.

The faucet body 12 in this embodiment includes a brass enclosure 32,three cartridge receptacles 34, a hot water inlet 36, and a cold waterinlet 38. As shown in FIG. 3, the faucet body 12 further includes anupper mixing chamber 40 and a lower chamber 42. The mixing chamber 40 inthis embodiment is a chamber that is in fluid connection with an outletof the hot water actuator 14, an outlet of the cold water actuator 16,and an inlet of the TMV assembly 18. As will be discussed below, thebypass chamber 42 is separated from the mixing chamber 40 primarily by awall 44, and is in fluid connection with the cold water inlet 38.

The hot water actuator 14 in this embodiment is a hot water actuatorcartridge that is secured within the left-most cartridge receptacle 34by a fastener 20. The handle 22 a is operably coupled to the hot wateractuator 14 to enable manual rotation thereof. In general, the hot wateractuator 14 includes an inlet 14 a, outlets 14 b, and a casing 14 c. Thecasing 14 c in this embodiment has a substantially cylindrical outersurface having a predefined diameter. The hot water actuator 14 includesa valve configured to selectively provide fluid connection between itsinlet 14 a and its outlet 14 b, based on the rotational position of theconnected handle 22 a. As shown in FIGS. 2-3, when the actuator 14 is inplace, the inlet 14 a is in fluid communication with the hot water inlet36 and the outlets 14 b are in fluid communication with the mixingchamber 40. Thus, the handle 22 a may be used to selectively cause hotwater to flow from the hot water inlet 36, which is under pressure, tothe mixing chamber 40. Hot water cartridges including such features ofthe hot water actuator 14 are known.

Similarly, the cold water actuator 16 in this embodiment is a cold wateractuator cartridge that is secured within the right-most cartridgereceptacle 34 by another fastener 20. The handle 22 b is operablycoupled to the cold water actuator 16 to enable manual rotation thereof.In general, the cold water actuator 16 includes an inlet 16 a, outlets16 b, and a casing 16 c. The casing 16 c in this embodiment has asubstantially cylindrical outer surface having the same predefineddiameter as the casing 14 c. The cold water actuator 16 is a valveconfigured to selectively provide fluid connection between its inlet 16a and its outlet 16 b, based on the rotational position of the handle 22b. As shown in FIGS. 2-3, when the actuator 16 is in place, the inlet 16a is in fluid communication with the cold water inlet 38 and the outlets16 b are in fluid communication with the mixing chamber 40. Thus, thehandle 22 b may be used to selectively cause cold water to flow from thecold water inlet 38, which is under pressure, to the mixing chamber 40.Such cold water cartridges are known.

The bypass chamber 42 is in fluid connection with the cold water inlet38. In general, the TMV assembly 18 is disposed in the middle receptacle34. In that position, the TMV assembly 18 is disposed within the mixingchamber 40 between the bypass chamber 42 and the spout 30. The TMVassembly 18 includes a housing having a spout outlet 46, mixing chamberinlets 48 and a bypass inlet 52. The spout outlet 46 is in fluidconnection with and coupled adjacent to the spout 30. The mixing chamberinlets 48 are in fluid connection with the mixing chamber 40. The bypassinlet 52 is in fluid connection with the bypass chamber 42. It will beappreciated that the TMV assembly 18 itself extends through an openingin the wall 44 between the mixing chamber 40 and the bypass chamber 42.

In general, the TMV assembly 18 has three modes. In a first or normalmode, the TMV assembly 18 is configured to provide fluid communicationbetween the mixing chamber 40 and the spout 30, but not with the bypasschamber 42. In the first mode, the water ejected from the spout 30constitutes a combination of the water that flows through the hot wateractuator 14 and the cold water actuator 16. The sealing element 50 isnormally “closed”, thereby preventing cold water from flowing from thebypass chamber 42. As a consequence, the temperature of the water iscomplete controlled via selective rotation of the handles 22 a, 22 b, asin the case of an ordinary faucet.

In a second or bypass mode, the TMV assembly 18 is configured to providefluid communication between the mixing chamber 40, the bypass chamber42, and the spout 30. To this end, the TMV assembly 18 includes a valveassembly having a sealing element 50 configured to move in a directionaway from the spout 30 (i.e. against the pressure of the cold water inthe bypass chamber 42) responsive to a temperature of water in themixing chamber 40 (i.e. within the TMV assembly 18) exceeding athreshold. The movement of the sealing element 50 away from the spout 30opens a fluid conduit through interior of the TMV assembly 18 betweenthe bypass inlet 52 (and hence the bypass chamber 42) and the spoutoutlet 46/mixing chamber inlets 48 (and hence the mixing chamber 40and/or the spout 30. The cold water under pressure in the bypass chamber42 thereby enters the interior of the TMV assembly 28 to lower thetemperature of the water therein, thus lowering the temperature of thewater exiting the spout 30. Thus, if the handles 22 a, 22 b arepositioned such that the temperature of water in the mixing chamber 40would exceed a predetermined maximum (e.g. 110° F.), then the TMVassembly 18 automatically mixes in additional cold water from the bypasschamber 40.

In the third or shut-down mode, the TMV assembly 18 operates to blockthe fluid communication to the spout 30 from the mixing chamber 40.Thus, in shut-down mode, the TMV assembly 18 does not allow water fromthe mixing chamber 40 to enter the spout 30. The TMV assembly 18 isconfigured to enter the third mode when the cooling water from thebypass chamber 42 cannot sufficiently cool the water provided to thespout 30 below the predetermined maximum temperature.

Thus, the TMV assembly 18 is configured to provide an override or bypassfunction that automatically adds cold water in the event that the waterin the mixing chamber 40 exceeds a predetermined temperature, andfurther provides a shut-down function when the added cold water cannotadequately cool the water provided to the spout 30 below thepredetermined temperature.

It will be appreciated that by employing a sealing element 50 that opensby moving against the pressurized cold water in the bypass chamber 42,the pressurized cold water in the bypass chamber 42 will under normalconditions will be urged toward its sealed position. By contrast, someprior art devices use a seal that moves toward the spout (with thepressured bypass water) to open, and thus must resist the pressure ofthe bypass cold water source even when the faucet is not in use.

FIG. 4a shows a more detailed plan view of an exemplary TMV assembly 18according to an embodiment of the present invention. The TMV assembly 18includes an external housing that comprises a body 54 coupled to andbetween a cap 56 and a lower housing 58. The body 54 forms a casinghaving a cylindrical outer surface with the same diameter as the casings14 c and 16 c. Because the casings of the cartridges 14, 16 and the TMV18 all have the same casing dimensions, the fittings for the variouselements may be uniform, thereby simplifying manufacturing, repair andrefitting. As shown in FIG. 4a , the lower housing 58 contains thebypass inlet 52, the body 54 includes the mixing chamber inlets 48, andthe cap 56 contains the spout outlet 46.

Referring again to FIGS. 2 and 3, as well as FIG. 4a , the lower housing58 is sized to fit through the opening in the wall 44, such that itresides in the bypass chamber 42. The body 54 resides in the mixingchamber 40. As will be discussed further below, a flared upper rim 98(see FIG. 4b ) of the lower housing 58 forms a tight fit within theopening in the wall 44, thereby ensuring that water from the bypasschamber 42 cannot enter the mixing chamber 40, except through theinterior of the TMV assembly 18 when the seal 50 is open (bypass mode).The O-ring washer 24 fits over the cap 56 and the retainer nut 20 is fitover the cap 56 and washer 24, and secures via threads to the outersurface of the center cartridge receptacle 34. The actuator cartridges14 and 16 are similarly secured within their respective receptacles 34with similar retainer nuts 20. The handles 22 a and 22 b are secured therespective cartridges 14, 16 in any conventional way.

The spout 30 is then coupled to the center retainer nut 20 via athreaded bushing 28. As discussed above, all water flowing through thespout 30 must come through the spout outlet 46 of the TMV assembly 18.

In general, when both handles 22 a, 22 b are in the off position, thenno water enters the mixing chamber 40 from either the hot water sourceor the cold water source (i.e. the plumbing system). The actuator 14prevents hot water from entering the mixing chamber 40, the actuator 16prevents cold water from entering the mixing chamber 40, and the TMVassembly 18 (and sealing element 50) prevents water from entering themixing chamber 40 and spout 30. If the cold water handle 22 b is movedto any of a plurality of on-positions, the actuator 16 will allow acorresponding flow of cold water into the mixing chamber 40. Thepressurized water will enter the mixing chamber inlets 48 and exit thespout outlet 46 to the spout 30. The spout 30 will thereby deliver coldwater.

If the hot water handle 22 a is also moved to any on-position, theactuator 14 will allow a corresponding flow of hot water into the mixingchamber 40. The pressurized water will mix with the cold water (assumingthe handle 22 b is still on) in the mixing chamber 40. The mixed hot andcold water will enter the mixing chamber inlets 48 of the TMV assembly18 and exit the spout outlet 46 into the spout 30. The spout 30 willthereby deliver a mix of hot and cold water. If the temperature of thewater in the mixing chamber 40, and particularly in the interior of theTMV assembly 18, is below the predetermined temperature, the TMVassembly 18 will retain the sealing element 50 such that water from thebypass chamber 42 does pass to spout output 46 or even the mixingchamber 40.

If, however, the temperature of the water in the mixing chamber 40 isabove the predetermined temperature, then the TMV assembly 18 will enterthe second or bypass mode of operation. Accordingly, the TMV assembly 18will cause the seal 50 to move in a direction away from the spout 30(i.e. against the pressure of the cold water in the bypass chamber 42,and thereby providing fluid communication between the mixing chamber 40and the bypass chamber 42. The cold water in the bypass chamber 42lowers the temperature of the water that exits the spout outlet 46. TheTMV assembly 18 in “bypass” mode maintains the position of the seal 50to modulate the flow of additional cold water from the bypass chamber 42to the extent necessary to ensure that the predetermined temperaturethreshold is not exceeded. If the handles 22 a, 22 b are subsequentlyadjusted (or turned off) such that the temperature of the water in themixing chamber 40 is consistently below the predetermined threshold, theTMV assembly 18 returns to the first mode and closes the sealing element50 to remove the fluid connection between the bypass chamber 42 and bothof the mixing chamber 40 and the spout outlet 46.

However, if the TMV assembly 18 is in the bypass mode, and theadditional cold water from the bypass chamber 42 cannot cool the waterto below the predetermined threshold, then the TMV assembly 18 entersthe shut-down mode. In the shut-down mode, the TMV assembly 18 seals thespout outlet 46 from the water in the mixing chamber 40. The TMVassembly 18 transitions back from the shut-down mode to the bypass modeonce the temperature of the water in the mixing chamber 40 falls belowthe predetermined threshold.

FIG. 4b shows a cutaway view of the TMV assembly 18 in the bypass mode,whereby fluid flows freely from the bypass inlet 52 to the spout outlet46. FIG. 4c shows an exploded perspective view of the TMV assembly 18.With reference to FIGS. 4b and 4c , the TMV assembly 18 includes, fromgenerally top to bottom, the cap 56, an upper spring 60, a thermal motor62, a piston 64, O-ring seals 66, 68, a shut down barrel 70. the O-ring24, the TMV body 54, a lower mandrel 72, a seating element 74, thesealing element 50, a lower seat retainer 76, a washer 78, a nut 80, alower spring 82, and the lower housing 58.

The drive structures of the TMV assembly 18 are the thermal motor 62,the piston 64, and the lower mandrel 72. The thermal motor 62 maysuitably be a thermal wax element or motor that expands, or in otherwords generates a linear force in the axially downward direction,responsive to heat. To this end, the thermal motor 62 contains wax thatexpands responsive to heat on the outer casing of the thermal motor,thus forming a form of temperature sensing element. The piston 64, whichmay suitably be a thin steel rod to handle the force of the thermalmotor 62, is coupled to the thermal motor 62 to receive the expansiveforce and stroke axially downward responsive thereto. The distal end ofthe piston 64 is received by the lower mandrel 72. The lower mandrel 72is a multi-radius shaft that is configured to retain, and translateaxial movement to, the sealing element 50.

Assembled onto the lower mandrel 72 is the sealing element 50. Thesealing element 50 may suitably be an EDPM rubber seal having adisk-like cylindrical body with a frustrum at the top to form thesealing surface. The mandrel 72 is configured to receive the seal 50from the bottom (as shown in FIG. 4b ). The seal 50 may be advancedaxially upward on the lower mandrel 72 until reaching an upper limitdefined by a wider radius of the mandrel 72. The seat retainer 76 is abrass structure configured to fit over the mandrel 72 below the sealingelement 50 and to engage and receive the sealing element 50. To thisend, the seat retainer 76 has an annular rim 86 having a diametersufficient to seat the bottom of the sealing element 50. The washer 78and nut 80 threadingly engage the bottom of the mandrel 72 and axiallyengage the seat retainer 76 to hold the seat retainer 76 and sealingelement 50 at their uppermost extent on the mandrel 72.

Essentially the motor 62, piston 64 and lower mandrel 72 drive train issuspended between the upper spring 60 and the lower spring 82, withinthe housing formed by the cap 56, the body 54 and the lower housing 58.The upper spring 60 is a conventional spring that provides axial springforce between its two ends. In this embodiment, the upper spring 60engages underside of the cap 56 on one end and the thermal motor 62 onthe other end. The upper spring 60 also surrounds a part of the thermalmotor 62 to help position the motor 62 along the axis of the cartridge18. To this end, the upper spring 60 has an outer helical diameter thatis less than a diameter the cap 56 and an inner helical diameter that issubstantially equal to, but slightly greater than, the outer diameter ofthe portion of the thermal motor 62 that it surrounds. It will beappreciated that the thermal motor 62 further includes a wide annularshelf 84 in its axial midsection that provides the axial engagingsurface for the spring 60.

Similarly, the lower spring 82 is similarly a conventional springproviding axial spring force between its two ends. In this embodiment,the lower spring 82 engages the inside of the lower housing 58 and, viathe lower seat retainer 76, the lower mandrel 72. To this end, the lowerspring 82 has an outer helical diameter that is less than a diameter ofthe lower housing 58 and an inner helical diameter that is substantiallyequal to, but slightly greater than, a portion of the lower seatretainer 76 that it surrounds. It will be appreciated that the lowerseat retainer 76 has a varying diameter that includes a wider portiontowards the top that provides an axial engagement surface for the lowerspring 82.

With respect to the housing, the cap 56 is generally cylindrical andincludes a top surface 92 and a cylindrical side 94. The top surface 92includes holes that form the spout outlet 46, and slots 96 for receivinga screwdriver or other tool for rotation of the cap 56. The cylindricalside 92 further includes a threaded outer bottom area 88 that engages acorresponding threaded top area 90 of the body 54. The threadingengagement of the cap 56 secures the cap 56 to the body 54 and retainsthe upper spring 60 within the housing.

The TMV body 54 is a generally cylindrical brass element having adiameter similar to the outer diameters of the hot water actuator 14 andcold water actuator 16, as discussed above, for ease of conformity offixtures, manufacturing, and part replacement. The TMV body 54 includesthe mixing chamber inlets 48 which consist of a plurality of holesdisposed around the body 54 at the same axial level. The side of thebody 54 includes an annular channel configured to receive the seal 24 atan axial level above the mixing chamber inlets 48. As will be discussedfurther below, the seal 24 forces all water that enters the spout 30 topass through the interior of the TMV body 54.

Also disposed within the TMV body 54 and against a lower side of theshelf 84 of the motor 62 is the shutdown barrel 70. The shutdown barrel70 is a device generally configured to selectively block the mixingchamber inlets 48. In particular, as will be discussed below in furtherdetail, the TMV assembly 18 is configured to move the shutdown barrel 70into an axial position in which the mixing chamber inlets 48 are blockedwhen the temperature of the water adjacent the motor 62 exceeds apredetermined threshold, and the thermal motor 62 is fully expanded tothe maximum stroke. This is the shut-down mode of the TMV assembly 18.

To this end, the shutdown barrel 70 has a substantially cylindrical side104 having a set of bores 106 arranged at the same axial level. Thebores 106 are configured to generally align with the mixing chamberinlets 48 under normal mode or bypass mode conditions. The cylindricalside 104 also includes to annular channels 110 for receivingcorresponding O-ring seals 66, 68. The shutdown barrel also includes atop surface 108 having a central opening for receiving the thermal motor62 and outlets 112 that provide fluid communication between the interiorof the shutdown barrel 70 and the spout outlet 46.

The lower housing 58 is a generally cylindrical cup-shaped structurewith a flared upper rim 98. The flared upper rim 98 receives afrustroconical portion of the seating element 74, which in thisembodiment is a Monel seal 74. The frustroconical portion of the Monelseal 74 receives the bottom of the body 54. The Monel seal 74 has asmaller bottom rim 102 that engages the sealing element 50 to providethe closing seal (in the first or normal mode) between the bypass inlet52 and the spout outlet 46 (i.e. between the bypass inlet 52 and theinterior of the TMV body 54.

The lower housing 58 is secured to the body 54 in this embodiment bybeing trapped between the wall 44 and the body 54. To this end, theflared upper rim 98 of the lower housing 58 (and the top rim of theMonel seal) is wider than the opening in the wall 44. As a result, thelower housing 58 can only travel downward until the flared upper rim 98is prevented from further travel by the wall 44. When the retainer nut20 (see FIGS. 1-3) is applied to secure the TMV assembly 18 in place, itplaces downward pressure on the body 54, which in turn pushes down onthe Monel seal 74. The downward pressure on the Monel seal 74 and thepositive interference between the wall 44 and the upper rim 98 cooperateto seal the opening in the wall 44, and to hold the lower housing 58 onthe overall TMV assembly 50.

Referring again to FIG. 3 as well as FIG. 4b , the TMV assembly 18 isseated such that the lower housing 58 is disposed in the bypass chamber42 (see also FIG. 3), and the interior of the lower housing 58 is influid communication with the bypass chamber 42 via the bypass inlet 52.The Monel seal 74 straddles the wall 44 between the mixing chamber 40and the bypass chamber 42. The Monel seal 74 and/or flared rim 98 of thelower housing 58 seal the opening in the wall 44 such that the water inthe bypass chamber 42 may only pass to the spout 30 and/or mixingchamber 40 via the interior of the TMV assembly 18 (or the cold wateractuator 16).

The TMV body 54 is disposed in the mixing chamber 40, as shown in FIG.3. The O-ring 24 seals the mixing chamber 40 from the spout 30 such thatthe only path of water from the mixing chamber 40 (or bypass chamber 42)is through the interior of the TMV body 54 and the cap 56.

FIG. 5 shows a cross-sectional view of the TMV assembly 18 of FIGS. 4a,4b and 4c in the normal mode of operation. In this mode, the sealingelement 50 is biased against the bottom rim 102 of the Monel seal 74 bythe lower spring 82. As such the bypass chamber 40 is not in fluidconnection with the spout outlet 46, the interior of the TMV body 54, orthe mixing chamber 40. In addition, the shutdown barrel 70 is disposedsuch that the bores 106 align with the mixing chamber inlets 48. It willbe appreciated that the bores 106 need not align exactly with the inlets48. Instead, the O-rings 66, 68 cooperate with the inner surface of thebody 54 to create a sealed chamber that allows fluid to flow freelybetween the O-rings 66, 68, and hence from the inlets 48 to the bores106.

As a result, as shown in FIG. 5, water under pressure in the mixingchamber 40 flows through the inlets 48, through the bores 106, out ofthe barrel outlets 112, and out of the spout outlet 46 into the spout30. The water passes the walls of the thermal motor 62, which operate asa temperature sensor by translating the heat from the water to theinternal wax element.

As discussed above, if the water in the mixing chamber 40 exceeds apredetermined threshold, the thermal motor 62 will expand, therebypushing the piston 64 and hence the lower mandrel 72 axially downwardagainst the bias of the lower spring 82. As a result, the sealingelement 50 moves in a direction away from the spout 30 and therefore offof the Monel seal 74. When the sealing element 50 moves off of the Monelseal 74, the TMV assembly 18 is in the bypass mode, as shown in FIG. 4b, and fluid from the bypass chamber 42 can enter the body 54 (and themixing chamber 40).

Referring to FIG. 4b , in the bypass mode, water from the bypass chamber42 enters the bypass inlets 52, and flows past the sealing element 50through the interior of the Monel seal 74, and then through a centralbore 114 in the body 54 through which the mandrel 72 also travels. Thewater then passes into the interior of the shutdown barrel 70, where itcan mix with the mixing chamber water that is received via the inlets 48and bores 106. The mixture of the mixing chamber water and bypasschamber water in the interior of the shutdown barrel 70 then travelsthrough the outlets 112, past the motor 62 and out of the spout outlet46 to the spout 30.

The goal of mixing in the cold bypass water is to modulate thetemperature of the water entering (and exiting) the spout 30 toward thepredetermined maximum temperature. In this embodiment, the predeterminedmaximum temperature is 110 degrees Fahrenheit. The bypass mode operationis self-regulating. Thus, as more cold water is mixed in, thetemperature of the water contacting the thermal motor 62 decreases,which in turn causes the thermal motor 62 to stop expanding, or even toretract. The final axial position of the piston 64 and lower mandrel 72ideally define the amount of bypass water that is necessary to maintainthe water at no more than the predetermined threshold temperature.Moreover, if the hot water actuator 14 is manipulated to shut off thehot water in the mixing chamber 40, then the temperature of the watercontacting the thermal motor 62 reduces to below the predeterminedmaximum. The thermal motor 62 retracts, and the bias spring 82 onceagain forces the sealing element 50 against the lower rim 102 of theMonel seal 74. As a result, the TMV assembly 18 re-enters the normalmode.

FIG. 6 shows a cross-section of the TMV assembly 18 in shutdown mode.The shutdown mode occurs when the add water from the bypass chamber 42is insufficient to lower the water temperature to the predeterminemaximum. In general, if the temperature of the water remains above thepredetermined maximum, the thermal motor 62 continues to apply axialforce downward on the piston 64 and hence the lower mandrel 72. Thelower mandrel 72, however, eventually bottoms out, or in other words, isprevented from further axial movement by the lower housing 58. As aresult, further axial expansion of the thermal motor 62 operates toforce the thermal motor 62 upward against the force of the upper spring60. After a sufficient upward travel of the thermal motor 62, the lowerO-ring seal 68 aligns with (or past) the mixing chamber inlets 48,thereby sealing off the mixing chamber 40 from the interior of theshutdown barrel 70, and hence the spout outlet 46 and spout 30. It willbe appreciated that in shutdown mode, water may still flow from thebypass chamber 42 in the same manner as the bypass mode.

It will be appreciated that the “predetermined temperature” of the TMVassembly 18 may be adjusted by rotating the cap 56. In particular,because the cap 56 and body 54 are coupled by corresponding helicalthreads, rotation of the cap 56 moves the cap axially upward ordownward, depending on the direction of rotation. Axial movement of thecap 56 moves the upper spring 60 and hence the motor 62. It will beappreciated that moving the motor 62 downward reduces the temperature atwhich the bypass mode is entered because the less expansion of thethermal motor 62 is needed to move the sealing element 50 off of theMonel seal 74. Alternatively, moving the motor 62 upward increases thetemperature at which the bypass mode is entered by additional expansionof the motor 62 is needed to move the seal off of the Monel seal 74.

Thus, the TMV assembly 18 shown in FIGS. 4-6 has several features andadvantages. It will be appreciated that the same TMV assembly 18 may beused in various faucets other than the faucet 10 of FIGS. 1-3. Forexample, FIG. 7 shows an alternative faucet 120 that does not havesingle faucet body in which the hot water actuator 14, the cold wateractuator 16, and the TMV assembly 18 all attach. Instead, the faucet 120of FIG. 7, each of the cartridges 14, 16 and 18 have individual housings122, 124 and 126, coupled by conduits 128, 130, and 132. The housing 126of the TMV assembly 18 operates as the mixing chamber, and the conduit132 from the cold water inlet to the bottom of the housing 126 and thebottom of the housing 126 constitutes the bypass chamber.

Some of the features of the exemplary embodiment described hereininclude that it provides temperature protection in accordance with ASSE1070 above the deck, and in such a way that the “normal mode” putspressure on the sealing element 50 that cooperates with the sealingforce of the lower spring 82. Another feature is that the mixing ofwater is down stream of the cartridges 14, 16. Among other things, thisallows the TMV assembly 18 to be serviced (e.g. adjustment of the cap56) in a way that is easily accessible by removing the spout 30.

Another embodiment of the invention does not include a lower housing ora Monel seal, but rather employs a similar sealing element 50 that formsa seal with the actual wall 44 between the bypass chamber 42 and themixing chamber 40.

It will further be appreciated that at least some of the benefits of thepresent embodiment of invention may be provided in designs that do notemploy a standard, uniform casing for the water cartridges and the TMVassembly 18. At least some of the advantages may be obtained even if thepositions of the chambers are not vertically displaced, but neverthelessallow for a motor adjustment via the spout opening. Further, it will beappreciated that other modifications of the TMV assembly 18 may be usedthat retain the feature of opening the bypass seal by moving the sealaway from the spout and/or mixing chamber, and further into the bypasschamber.

I claim:
 1. A valve assembly for a faucet assembly, comprising: ahousing including at least a first inlet configurable to receive waterfrom a first source, a spout outlet in fluid connection with the firstinlet, and a second inlet configurable to receive water from a secondsource; a thermal motor disposed within the housing, the thermal motorconfigured to impart linear force in a first axial direction responsiveto heat; and a seal operably coupled to the thermal motor to move in thefirst axial direction in response to the imparted linear force, the sealhaving a sealed position and at least one unsealed position, the seal inthe sealed position forming a fluid seal between the second inlet andthe spout outlet, wherein the sealed position is axially between themotor and the at least one unsealed position, and wherein movement ofthe seal in the first axial direction in response to the imparted linearforce breaks the formed fluid seal to allow fluid flow within thehousing from the second inlet to the spout outlet.
 2. The valve assemblyof claim 1, wherein: the first inlet is part of a first set of inletsconfigured to receive water from the first source; and the second inletis part of a second set of inlets configured to receive water from thesecond source.
 3. The valve assembly of claim 1, further comprising afirst spring disposed between the housing and the seal, the first springconfigured to provide a bias force on the seal opposite the impartedlinear force.
 4. The valve assembly of claim 1, further comprising anaxially moveable barrel having a third inlet, and wherein additionallinear force imparted by the thermal motor moves the barrel from a firstbarrel position in which the first inlet and the third inlet are influid communication within the housing, to a second barrel position inwhich the first inlet and the third inlet are not in fluid communicationwithin the housing.
 5. The valve assembly of claim 4, further comprisinga first spring disposed between the housing and the seal, the firstspring configured to provide a bias force on the seal opposite theimparted linear force.
 6. The valve assembly of claim 5, furthercomprising a second spring operably coupled to provide force between thehousing and the thermal motor to urge the motor and the barrel in thefirst axial direction.
 7. The valve assembly of claim 6, wherein thefirst spring and the second spring are configured such that the impartedlinear force causes compression of the first spring before causingcompression on the second spring.
 8. The valve assembly of claim 1,wherein the thermal motor is a thermal wax motor.
 9. A valve assembly,comprising: a housing; a thermal motor disposed within the housing, thethermal motor configured to impart linear force in an axial direction; aseal operably coupled to the thermal motor to move in the axialdirection in response to the imparted linear force, the seal having asealed position and at least one unsealed position, the seal in thesealed position forming a fluid seal, wherein the sealed position isaxially between the motor and the at least one unsealed position; and ashutdown barrel affixed to the thermal motor, the shutdown barrelconfigured to form a second seal sealing a first inlet in the housing ina first position, and allowing fluid communication through the firstinlet in a second position.
 10. The valve assembly of claim 9, furthercomprising a first spring disposed between the housing and the seal, thefirst spring configured to provide a bias force on the seal opposite theimparted linear force.
 11. The valve assembly of claim 10, furthercomprising a second spring disposed between the housing and the motor,the second spring configured to provide a bias force between the motorand housing opposite the bias force provided by the first spring. 12.The valve assembly of claim 11, wherein the housing includes anadjustable cap, and wherein the second spring engages the adjustablecap, such that axial adjustment of the cap causes axial adjustment of atleast a part of the second spring.
 13. The valve assembly of claim 12,wherein the adjustable cap includes a spout outlet configurable to emitwater received at the first inlet.
 14. The valve assembly of claim 9,wherein the shutdown barrel includes an annular channel, and wherein thevalve assembly further comprises a first O-ring seal disposed within theannular channel, the first O-ring seal configured to form the secondseal.
 15. A valve assembly for a faucet assembly, comprising: a housing;a thermal motor disposed within the housing, the thermal motorconfigured to impart linear force in a first axial direction; a seal ona mandrel operably coupled to the thermal motor to move in the axialdirection in response to the imparted linear force, the seal having asealed position and at least one unsealed position, the seal in thesealed position forming a fluid seal, wherein the sealed position isdisposed axially between the motor and the at least one unsealedposition; wherein the imparted linear force causes the mandrel to movein the first axial direction until the mandrel engages a stop, andwherein further imparted linear force after the mandrel engages a stopcauses the thermal motor to move in a second axial direction.
 16. Thevalve assembly of claim 15, wherein the movement of the seal in thefirst axial direction breaks the formed fluid seal.
 17. The valveassembly of claim 16, wherein the movement of the thermal motor in thesecond axial direction causes a second seal to form within the housing.18. The valve assembly of claim 17, further comprising a first springdisposed between a first end of the housing and the seal, the firstspring configured to provide a bias force on the seal opposite theimparted linear force.
 19. The valve assembly of claim 18, furthercomprising a second spring disposed between a second end of the housingand the motor, the second spring configured to provide a bias forcebetween the motor and housing opposite the bias force provided by thefirst spring.
 20. The valve assembly of claim 1, further comprising arim disposed between the motor and the seal, and wherein the seal in thesealed position engages the rim to form a fluid seal between the secondinlet and the spout outlet.